Amphtml: add instructions for mac osx and windows validator dependencies

[erwinmombay]

https://github.com/ampproject/amphtml/blob/master/validator/README.md does not contain Mac OSX and Windows installation steps for dependencies

[levidurfee]

This is what worked for me on OSX.

brew install protobuf

Result:

Editor support and examples have been installed to:
  /usr/local/opt/protobuf/share/doc/protobuf

Python modules have been installed and Homebrew's site-packages is not
in your Python sys.path, so you will not be able to import the modules
this formula installed. If you plan to develop with these modules,
please run:
  mkdir -p /Users/USERNAME/Library/Python/2.7/lib/python/site-packages
  echo 'import site; site.addsitedir("/usr/local/lib/python2.7/site-packages")' >> /Users/USERNAME/Library/Python/2.7/lib/python/site-packages/homebrew.pth

So I ran:

mkdir -p /Users/USERNAME/Library/Python/2.7/lib/python/site-packages
echo 'import site; site.addsitedir("/usr/local/lib/python2.7/site-packages")' >> /Users/USERNAME/Library/Python/2.7/lib/python/site-packages/homebrew.pth

Then I installed JDK.

brew tap caskroom/cask
brew install Caskroom/cask/java

Then I was able to run gulp validator

[honeybadgerdontcare]

Erwin was experiencing some issues with .DS_Store files. Here are my notes about that:

Macs create a file called .DS_Store every time a user enters that director. amphtml-validation tries to traverse it as a directory and throws an error. Deleting the file allows amphtml-validation to work, but if the user enters the directory (e.g. component/test/...) the .DS_Store file will be created again.

[erwinmombay]

/cc @mrjoro

[erwinmombay]

thanks so much @levidurfee

[ampprojectbot]

This issue hasn't been updated in awhile. @erwinmombay Do you have any updates?

[Enriqe]

This worked for me! @erwinmombay I think we should really add this to the documentation :)

[erwinmombay]

@Enriqe oops. i always thought we added this... ill send out a PR

[Exlord]

how about windows??

when I run gulp validator --update_tests to build .out file

[[build.py CheckPrereqs]] - entering ...
Sorry, this script assumes Linux or Mac OS X thus far. Please feel free to edit the source and fix it to your needs.
[15:56:24] The following tasks did not complete: validator
[15:56:24] Did you forget to signal async completion?

[honeybadgerdontcare]

@Exlord as the script suggests, maybe you can update it to work for windows?

[Exlord]

@Exlord as the script suggests, maybe you can update it to work for windows?

How? The script just says do it, does not say how?? And I don't know python!